M bauer



March 1955 J. M. BAUER 2,703,049

MOUNTING OF THE LARGE GEAR CAM FOLLOWER IN I PIVOTED PLATEN TYPE OF PRINTING PRESSES Filed Oct. 12, 1951 ATTORNEYS United States Patent MOUNTING OF THE LARGE GEAR CAM FOL- LOWER 1N PIVOTED PLATEN TYPE OF PRINTING PRESSES Joseph M. Bauer, Green Bay, Wis.

Application October 12, 1951, Serial No. 251,097 1 Claim. (Cl. 101-297 This invention appertains to pivoted platen type of printing presses, and more particularly to improvements in the mounting of the large gear cam follower or roller which regulates the pressure between the printmg form and the platen.

In the operation of standard type of platen printing presses, certain pressure must be exerted between the printing form and the platen. This pressure must be constant to make for uniform printing and to avoid blurring or slurring in the finished printed matter.

Most press manufacturers utilize the same type method of operating the platen, and as the machine ages the operating cam follower or roller and raceway 1n the main gear cam wheel becomes worn. This tends to reduce the pressure and as a result the print is not printed clear and sharp. This is especially true when printing a full size form or a form that is locked too far above the center of the platen. When wear occurs, particularly in the raceway of the large gear cam, the gear cam must be taken off of the press, resurfaced, and an oversized follower or roller made to fit the new raceway. This requires from sixteen to twenty-four hours labor to complete the job.

Therefore, one of the primary objects of my invention is to provide an improved type of mounting for the cam follower or roller in which an adjustment can be made to increase the pressure between the platen and printing form to insure proper locking without removing the main gear cam wheel from the machine or resurfacing either the raceway or the follower.

Another important object of my invention is to provide an eccentric type roller stud upon which the cam follower or roller is mounted so that by simply turning the eccentric stud, the roller may be ad usted in the raceway in a matter of ten to fifteen minutes without utilizing additional material or machining of any of the parts.

A further object of my invention is to provide a simple, practical and reliable construction that is economical to manufacture, easy to assemble and positive in its operation. With the above and other objects in view, which will more readily appear as the nature of my invention is better understood, the same consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed. A preferred and practical embodiment of my invention is shown in the accompanying drawings, in which:

Figure l is a fragmentary elevational view, partly in section, illustrating the cam follower or roller secured to the platen of a printing press by means of the roller stud constructed in accordance with my present invention, and received in the raceway of the main gear cam wheel;

Figure 2 is an enlarged fragmentary elevational view showing the various parts in the position illustrated in Figure l and before any wear has occurred;

Figure 3 is a view similar to Figure 2 of the drawings, a part of the eccentric stud being broken away to illustrate details in construction, and showing how the main gear cam roller may be adjusted from the full line position to the dotted line position when the raceway or roller becomes worn;

Figure 4 is a fragmentary horizontal longitudinal section taken on the line 44 of Figure 2 and looking in the direction of the arrows; and

Figure 5 is a fragmentary vertical longitudinal section taken on the line 5--5 of Figure 2 and looking in the direction of the arrows.

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views, the letter A generally indicates my improved cam roller and its eccentric stud mounting.

In Figure l of the drawing, I have illustrated rather diagrammatically one conventional manner of locking the printing form and platen. In this construction the large gear cam wheel 10 of a printing press is mounted for rotation about a driven shaft 11 and has provided in one surface thereof a cam raceway 12. The raceway 12 is defined by an inner track surface 13 and an outer track surface 14. The raceway 12 is also formed with an inwardly projecting portion 15 at one end thereof as shown. In the position illustrated in Figure 1, the platen 16 is in its locked position and the paper P is held firmly between the platen 16 and the printing form 17 with the cam follower or roller 18 snugly fitting between the two surfaces 13 and 14 of the raceway 12.

It is to be noted, however, that the follower or roller 18 holds the platen 16 in its locked position primarily by riding on the inner surface 13 of the cam raceway 12, and most of the wear takes place along the track surface 13 or on the roller per se. When the large gear cam wheel 10 is rotated so that the cam follower or roller 18 is guided into the inwardly projecting portion 15, the platen 16 will obviously be moved to its open position, the finished print P ejected, and a new print inserted. All of the above is common in the conventional pivoted platen type of printing presses. However, in the present instance, the cam follower 18 is shown secured to the platen 16 through a projection or ear 19 by means of a roller stud S. In some types of presses the stud is mounted on the end of a bar, lever, etc., but for the purpose of illustrating my invention I have shown the ear 19 as having an aperture formed adjacent its outer end which receives the reduced portion 20 of my eccentric stud S. The reduced portion 20 is eccentrically mounted on one end of a barrel 21, and has formed on its other end a further reduced threaded portion 23. The threaded portion 23 is provided with a transverse slot 24, the purpose of which will be readily apparent as the description proceeds. It is important to note that the circumferences of the barrel 21, reduced portion 20 and threaded portion 23 are all perfectly circular, with the central axis of the reduced portion 20 and threaded portion 23 being aligned and lying in the same plane with the reduced portion 20 mounted eccentrically or off-center from the central axis of the barrel 21. As is readily apparent, barrel portion 21 is snugly received in the bore 25 of the cam follower or roller 18 and the eccentric stud S is securely held to the ear 19 of the platen 16 by means of a lock nut 26. The barrel portion 21 of the stud S, and the central bore 25 of the cam roller 18 are highly machined to reduce the friction resulting from the rolling contact of the cam follower with surfaces 13 and 14 of the raceway 12.

In the event that excessive wear takes place in the raceway 12 and particularly on the surface 13 thereof, or if the outer surface of the roller 18 becomes worn, a looseness will develop as illustrated in Figure 3 of the drawing. This looseness or play will not permit the platen 16 to lock and press firmly against the printing form 17, and as a result thereof the printed matter P will not be sharp or clear. In order to overcome this defect, it is merely necessary to insert a screw driver or like tool in the slot 24 of the stud S and rotate it in the direction of the arrow (Fig. 3) until the cam follower 18 is moved to the dotted line position as shown. In this position the platen 16 will continue to be firmly held and pressed against the printing form 17 to provide a sharp clear print.

From the foregoing, it is believed that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will, of course, be understood that changes in the form, proportion and minor details of construction may be resorted to without departing from the spirit of the invention or the scope of the appended claim.

I claim:

In a printing press, a printing form, a platen mounted for pivotal movement beneath said form, and means associated with said platen to hold and press a print therebetween and for adjusting and maintaining a uniform pressure between the platen and printing form during the printing process regardless of wear including, a main gear cam wheel adjacent one side of said platen having a tortuous raceway formed in the inner surface about its central axis, said raceway having an inner track surface and an outer track surface, a cam roller rotatably received in the raceway, a stud having a large barrel portion, a reduced portion mounted on one end of said barrel portion, a reduced threaded portion mounted on the opposite end of said reduced portion, all of said stud portions being circular in circumference and the reduced portion eccentrically mounted on said barrel portion, said barrel portion being rotatably received in said cam roller, a rearwardly projecting ear on said platen adjacent said raceway of said main gear cam wheel receiving said reduced portion of the eccentric roller stud, whereby, said reduced portion is rockably secured to said platen, a lock nut threaded over said threaded portion to hold the stud to said platen, and a transverse slot in said threaded portion whereby the stud may be rotated, to adjust the cam roller to ride on the inner track surface of said raceway and to insure the same steady and uniform pressure between the platen and the printing form regardless of the wear and condition of the cam roller.

References Cited in the file of this patent UNITED STATES PATENTS 520,775 Fowler et al June 5, 1894 587,156 Nold July 27, 1897 912,727 Pinkham Feb. 16, 1909 916,702 Hartt Mar. 30, 1909 1,289,273 Root Dec. 31, 1918 1,360,063 Waters Nov. 23, 1920 1,612,500 Ezbelent Dec. 28, 1926 1,906,304 Barrett May 2, 1933 2,119,880 Horton June 7, 1938 2,497,800 Root Feb. 14, 1950 2,602,396 Jirousek July 8, 1952 

